Blue Hour palette
Atlas Library
Dark anchor, working middle, light release: #4677b1, #0081a2, #008685, #349dbf, #1fa3a2 form a analogous blue hour set with somewhere to stand at every lightness. Made for book covers that read at thumbnail size.
skybluehourfive-stop
#4677b1
#0081a2
#008685
#349dbf
#1fa3a2
The generator opens with #4677b1 as the primary and the next two stops as secondary and accent — adjust, check contrast, and export tokens or CSS from there.